Electric furnace



Sept- 25, 1923. 1,469,033

W. F. BLEECKER ELECTRIC FURNACE Filed July 8, 1920 I N VEN TOR.

)1! F BLEECKER ATTORNEY.

Patented Sept. 25, 1923.

UNITED STATES 1,469,033" PATIENT orrlca.

WARREN F. BLEECKER,-OF BOULDER, COLORADO, ASSIGNOE TO THE TUNGSTEN PROD- U QTS COMPANY, OF BOULDER, COLORADO, A CORPORATION OECOLORADOi ELECTRIC FURNACE.

Application flied July 8,

To all whom it may concern:

Be it known that I, VVARnnN F. Bncncrrrzn, a citizen of the United States, residin at Boulder, in the county of Boulder and tate of Colorado, have invented certain new and useful lmyn'ovements in Electric Furnaces. of which-the following is a specification.

This invention relates to electric furnaces and its primary object is to rovide a furnace of this type which is particularly adapted for use in a reduction process such as the process of reducing tungstic oxides to metallic tungsten described in my application for patent Serial No. 394,630, filed July 8, 1920.

Another object of the present 1nvention vis to provide a furnace of the character above referred to which continuously discharges the product of reduction in ratio to a continuous feed of fresh material and which in this respect differs from furnaces of the intermittent type in which a charge of material is packed into a reduction chamher to remain until the process of reduction is completed.

An embodiment of my invention has been shown in the accompanying drawings in the various views of which like parts are similarly: designated, and in which- Figure 1 represents a vertical section of the furnace, and p Figure 2, a section taken on the line 2--2, Figure 1.

Referring more specifically to the drawings, the reference character 2 designates a structure of substantially rectangular form made up of a steel shell 5 and a. heavy refractory lining 6 preferably composed of either carbon or electrically fused magnesite and providing a combined heating and reduction chamber 7. The chamber is covered by a suitable reenforced arched roof 8 which at one end has a feed hopper 9 through which the charge is introduced.

An inclined floor 10 preferably composed of carbon or graphite rods slants downwardly in the chamber from its wall below the feed hopper and terminates before it reaches the opposite wall of the same to provide a space 12 through which the material is discharged onto a similarly made second floor 13. g The last-mentioned floor slants in an. opposite direction below the other and communicatcs at its lower end with a hopper 14 which 1920. s r m No. 394,629.

discharges the product of the reduction process into a conveniently placed receptacle or conveyor.

The dischawre hopperis preferably provided with one or two gates 15 which control the outflow of material. The wall of the structure adjacent the point of nearest approach. of the two floors has an opening 16 norinaEiy closed by a door 17 through which if necessary the material may be rabbled to assist and expedite its downward flow.

Hand tools may be used for this purpose or a mechanically operated rake made of graphite or i'\i ;h-Inelting point steel may be installed in connection with a plunger or other suitable actuating mechanism. I desire it u iderstood however, that gravity is the force principally depended on to effect the downward movement of the material along the floors and that the rabbling means is employed merely as an auxiliary to regulate said movement so that when the material reaches the end. of the lower floor the reduc tion process shall have been completed.

The heating medium of the furnace consists in its preferred form of a pair of longitudinally alined electrodes 18 extending through water-cooled boxes 19 in opposite walls of the furnace and spaced from each other to provide a jumping gap for the vol taic are. t a

A solid or granular electrical resistor may be employed in the place of the electrodes if so desired.

In the operation-ofthe furnace the charge placed in the hopper 9 is uniformly distributed over the surface of the upper floor by grzii'vity with or without the aid of mechani cal feeding devices.

The movement of the material along the floor is aided as hereinbefore explained by mechanically or manually operated rabbling means introduced into the reduction chamher. through the opening 16 in the wall of the furnace, it being desirable that the process of reduction is practically completed when the charge falls across the end of the upper floor.

Further reduction takes place as the material flOWS downwardly over the lower floor and is entirely completed at the time of its discharge into the hopper 14. The charge is cooled in the hopper and removed therefrom as convenient, either continuously or intermittently.

Vhat I claim and desire to secure by Let-- ters-Patent is:

1. A reduction furnace comprising a closed chamber having a feed opening and a discharge-opening, a floor composed of carbon rods slanting downwardly beneath the feed opening, in communication With the discharge opening and an electric heating medium beneath the floor.

2. In a reduction furnace, a heat conducting floor composed of carbon rods.

3. A reduction furnace comprising a closed chamber having a feed opening and a discharge opening a floor composed of carbon rods in communication with the discharge opening, and an electric heating medium above the floor.

In testimony whereof I have affixed my signature.

\VARREN F BLEECKER. 

